(Adds Tanzania mining ban details, background)
Oct 23 (Reuters) - Petra Diamonds Ltd's PDL.L first quarter revenue fell by 17 percent after the government of Tanzania last month seized a consignment of diamonds from its Williamson mine.
The owner of the Cullinan mine in South Africa has been hit by a crackdown on mining firms in Tanzania, where the government is attempting to secure more revenue from the sector.
The Tanzanian government confiscated a consignment of diamonds from the Williamson mine, which is majority-owned by Petra, alleging the company had under-declared the value of the stones by about half.
Petra has denied the charge.
The London-listed company said on Monday its revenue was $78.7 million in the quarter ended Sept. 30, while net debt rose to $614 million, from $555 million as of June 30.
Shares in Petra rose as much as 4 percent, before paring gains to trade up 2.75 percent at 84 pence by 0801 GMT. Petra maintained its full-year production guidance of between 4.8 million carats and 5.0 million carats. has also faced strikes in South Africa over pay, rent and housing allowances and demands for medical expenses.