* Busch-Holding raises stake from 15 percent
* Says now considers itself anchor investor
* Says will support Pfeiffer
* Shares rise to record high (Adds Busch-Holding statement, shares)
FRANKFURT, Oct 15 (Reuters) - German vacuum pump maker Busch-Holding GmbH increased its stake in rival Pfeiffer Vacuum to 27.2 percent from 15 percent and said on Thursday it now considered itself an anchor investor in the group.
The news pushed shares in Pfeiffer Vacuum up as much as 5 percent to a record high.
Busch had bought a stake in Pfeiffer in a surprise move last month in hopes that robust business from chipmakers and industrial customers will keep its stock rising.
"We are happy that the opportunity arose to significantly increase our holding so soon after our initial investment," Sami Busch, one of Busch's five managing partners, said in a statement.
"As a shareholder, we want to support Pfeiffer Vacuum in taking advantages of business opportunities in a market that we know well," Busch added.
It said at the time it had no plans to raise its stake in Pfeiffer to 30 percent, which would trigger a mandatory takeover offer under German law, and did not seek to influence strategic decisions at the company.
Pfeiffer makes pumps used by semiconductor firms, industrial companies and makers of analytical devices such as scanning electron microscopes. Family-owned and unlisted Busch says it is one of the world's largest makers of vacuum pumps, blowers and compressors supplying all industry sectors. (Reporting by Maria Sheahan; Editing by Harro ten Wolde and Victoria Bryan)