ZURICH -(Dow Jones)- Roche Holding AG (ROG.VX) Tuesday exerted pressure on takeover target Illumina Inc. (ILMN), claiming it has other options should the U.S. gene decoder keep resisting the Swiss drug maker's hostile $5.7 billion bid. "The proposed acquisition of Illumina would strengthen our diagnostics division as gene sequencing will be a key technology going forward, and both would benefit from a rapid merger," Roche Chairman Franz Humer said Tuesday at the company's annual general meeting. "However, this is an area where we have other options should the transaction fail over price," Humer told Roche shareholders. Roche is offering $44.50 a share for the San Diego-based group, an offer it views as "full and fair," but one that Illumina has dismissed as too low. The Basel-based company said last month it is still offering the same price for Illumina shares, valuing the buyout at $5.7 billion, with the period now extended to 6:00 p.m., New York City time, on March 23. Responding to Roche's tender offer extension, Illumina said, "An extremely low number of shares have been tendered, consistent with our view--and that of our stockholders--that Roche's offer doesn't reflect Illumina unique leadership position, business performance and future prospects." At 1350 GMT, Roche shares were little changed at CHF159.40, leaving them up almost 15% from a year earlier. -By Neil MacLucas, Dow Jones Newswires; +41 43 443 8046; neil.maclucas@dowjones.com