* Amends warehouse line of credit with Wachovia Bank

* Converts credit line to $145.7 mln secured debt facility

* Extends maturity by 3 years to July 2012

* Shares rise as much as 19 pct

July 15 (Reuters) - NewStar Financial Inc (NEWS.O: Quote, Profile, Research) said it has amended its credit line with Wachovia Bank to convert it into a $145.7 million, three-year, secured term debt facility, sending its shares up as much as 19 percent.

The credit facility has been structured to finance a static pool of existing loans of about $228.4 million, which is expected to generate sufficient cash flow from interest and principal collections to repay the loan over its term, the company said in a statement.

NewStar, a specialized commercial finance company, said the amendment extends the maturity of the credit line by three years to July 15, 2012.

The company said the credit amendment better matches the maturity profile of the assets it funds.

"Approximately 87 percent of our loan portfolio is now funded with long-term debt and equity capital," Chief Financial Officer John Bray said.

Shares of the company were up 26 cents at $1.96 in afternoon trade on Nasdaq. They touched a high of $2.02 earlier. (Reporting by Sakthi Prasad in Bangalore; Editing by Unnikrishnan Nair)