Analyze the relationship between 'Lafarge' and 'cement' within the context of the input sentence.
Options: founded by, platform, product/material produced, position held

The firm has just named Wolfgang Reitzle as an advisory partner the very same Wolfgang Reitzle who hired Perella Weinberg as an adviser to steer the rocky $44bn (£28.2bn) merger between his Swiss cement firm Holcim and its French rival Lafarge (EUREX: 504482.EX - news ) .
product/material produced