(CNN) -- With the two sides unable to come to contract terms, the NFL locked out its referees before the preseason began. Here are some of the issues that are on the table between the NFL, its 32 owners and the 121 officials. PAY . The money to pay officials comes from a pot of $18 million funded by the league. The NFL wants an increase in the average salary for officials, who are part-time employees, from $149,000 to $189,000 by 2018. Referees (the head officials) and officials who qualify for postseason games would make more, the league said. The raises each year would fall between 5% and 11%, the league said. The officials have asked for more, but have not publicly disclosed how much. They say the league, which has revenues of more than $9 billion per year, can afford it. NFL: Packers should have won . RETIREMENT PLAN . The league wants to switch from a pension plan to a 401k plan. The league said in a July statement: "No game official will lose any vested pension benefit under our proposal and the clubs will fully fund all pension obligations." But the executive director of the referees association said in an open letter to the media last week that plan would transfer long-term investment risk to the officials and would cut the league's financial obligation by 60%. Tim Millis said 18 of the league's teams have some form of defined-benefit program rather than a 401k system. The league said their plan will give the officials a larger retirement benefit. The officials have proposed that only new hires be moved to the 401k plan. SI: NFL Holds firm in negotiations . MORE RESERVE CREWS . According to Peter King of Sports Illustrated the league would like to add three crews of seven people in reserve with the option to use these referees to replace underperforming officials. That would add 21 officials to the pool and officials fear it would affect their job security. Referees are only paid for games worked, so anyone who was "benched" would lose pay. Chorus for NFL referees grows . FULL-TIME OFFICIALS . Right now each official works a full-time job and refs in his free time. Officials also have to watch game tape, file reports to the league office and take a weekly written test on the rules. One veteran referee told ESPN that all that, coupled with keeping in shape, takes 30 hours a week. The league wants to hire seven full-time officials and have them handle training and scouting. The officials' association has said it would OK with that, if the referees were paid a fair amount. Photos: Blown calls in sports history .
There are 121 officials locked out by the National Football League .
They disagree with league on how much should be added to compensation pool each year .
The league wants a 401k, officials want to stick with a pension .
League wants to add 21 more officials but not everyone would work each week .
(CNN) -- With the two sides unable to come to contract terms, the NFL locked out its referees before the preseason began. Here are some of the issues that are on the table between the NFL, its 32 owners and the 121 officials. PAY . The money to pay officials comes from a pot of $18 million funded by the league. The NFL wants an increase in the average salary for officials, who are part-time employees, from $149,000 to $189,000 by 2018. Referees (the head officials) and officials who qualify for postseason games would make more, the league said. The raises each year would fall between 5% and 11%, the league said. The officials have asked for more, but have not publicly disclosed how much. They say the league, which has revenues of more than $9 billion per year, can afford it. NFL: Packers should have won . RETIREMENT PLAN . The league wants to switch from a pension plan to a 401k plan. The league said in a July statement: "No game official will lose any vested pension benefit under our proposal and the clubs will fully fund all pension obligations." But the executive director of the referees association said in an open letter to the media last week that plan would transfer long-term investment risk to the officials and would cut the league's financial obligation by 60%. Tim Millis said 18 of the league's teams have some form of defined-benefit program rather than a 401k system. The league said their plan will give the officials a larger retirement benefit. The officials have proposed that only new hires be moved to the 401k plan. SI: NFL Holds firm in negotiations . MORE RESERVE CREWS . According to Peter King of Sports Illustrated the league would like to add three crews of seven people in reserve with the option to use these referees to replace underperforming officials. That would add 21 officials to the pool and officials fear it would affect their job security. Referees are only paid for games worked, so anyone who was "benched" would lose pay. Chorus for NFL referees grows . FULL-TIME OFFICIALS . Right now each official works a full-time job and refs in his free time. Officials also have to watch game tape, file reports to the league office and take a weekly written test on the rules. One veteran referee told ESPN that all that, coupled with keeping in shape, takes 30 hours a week. The league wants to hire seven full-time officials and have them handle training and scouting. The officials' association has said it would OK with that, if the referees were paid a fair amount. Photos: Blown calls in sports history .
contract terms, the NFL locked out its referees funded by the league. The NFL wants an increase the league said. The raises each year would fall officials have asked for more, but have not publicly disclosed how much. They say the league, from a pension plan to a 401k plan. The league officials. That would add 21 officials to the shape, takes 30 hours a week. The league wants to