HRPT Properties Trust increased the size of a public offering of common stock by 10 million shares to 30 million shares.

The real estate investment trust also said late Thursday that it priced the offering at $7.25 per share.

HRPT plans to use the offering's net proceeds to pay back outstanding amounts under a $750 million revolving credit agreement and for general corporate purposes such as potential acquisitions.

HRPT gave the underwriters a 30-day option to buy up to an additional 4.5 million shares to cover any overallotments.

The offering is expected to close on Wednesday.

Shares of HRPT fell 18 cents, or 2.4 percent, to $7.32 in afternoon trading. Over the past year, the stock has traded in a range of $2.91 to $8.13.